<?php

if (!defined('ABSPATH')) {
    die('You are not allowed to call this page directly.');
}

abstract class MeprBaseMetaModel extends MeprBaseModel
{
    /**
     * The type of object being processed
     *
     * @var string
     */
    private $object_type;

    /**
     * The database table name for object meta
     *
     * @var string
     */
    private $meta_table;

    /**
     * Constructor
     *
     * @param mixed $obj The object.
     */
    public function __construct($obj = null)
    {
        $this->object_type = $this->object_type();
        $this->meta_table  = $this->object_type . '_meta';
    }
    /**
     * Get a metadata field for a given object
     *
     * Mimics the behavior of 'get_{type}_meta'
     *
     * @param string  $meta_key Meta key.
     * @param boolean $single   Return a single value or not.
     */
    public function get_meta($meta_key, $single = false)
    {
        $mepr_db = MeprDb::fetch();

        return $mepr_db->get_metadata($mepr_db->{$this->meta_table}, "{$this->object_type}_id", $this->id, $meta_key, $single);
    }

    /**
     * Add a metadata field for a given object
     *
     * Mimics the behavior of 'add_{type}_meta'
     *
     * @param string $meta_key   Meta key.
     * @param string $meta_value Meta value. Will be serialized if an object or an array.
     * @param string $unique     Value should be unique for the meta_key/object_id.
     *
     * @return integer|false The meta ID on success, false on failure.
     */
    public function add_meta($meta_key, $meta_value, $unique = false)
    {
        $mepr_db = MeprDb::fetch();

        return $mepr_db->add_metadata($mepr_db->{$this->meta_table}, "{$this->object_type}_id", $this->id, $meta_key, $meta_value, $unique);
    }

    /**
     * Update a metadata field for the object
     *
     * Mimics the behavior of 'update_{type}_meta'
     *
     * @param  string $meta_key   Meta key.
     * @param  string $meta_value Meta value. Will be serialized if an object or an array.
     * @param  string $prev_value Prev value.
     * @return integer|boolean Meta ID if the key didn't exist, true on successful update, false on failure.
     */
    public function update_meta($meta_key, $meta_value, $prev_value = '')
    {
        $mepr_db = MeprDb::fetch();

        return $mepr_db->update_metadata($mepr_db->{$this->meta_table}, "{$this->object_type}_id", $this->id, $meta_key, $meta_value, $prev_value);
    }

    /**
     * Delete metadata for the specified object & meta_key.
     *
     * @global wpdb $wpdb WordPress database abstraction object.
     *
     * @param string $meta_key   Metadata key.
     * @param mixed  $meta_value Optional. Metadata value. Must be serializable if non-scalar. If specified, only delete
     *                           metadata entries with this value. Otherwise, delete all entries with the specified meta_key.
     *                           Pass `null, `false`, or an empty string to skip this check. (For backward compatibility,
     *                           it is not possible to pass an empty string to delete those entries with an empty string
     *                           for a value.).
     *
     * @return boolean True on successful delete, false on failure.
     */
    public function delete_meta($meta_key, $meta_value = '')
    {
        $mepr_db = MeprDb::fetch();

        return $mepr_db->delete_metadata($mepr_db->{$this->meta_table}, "{$this->object_type}_id", $this->id, $meta_key, $meta_value);
    }

    /**
     * Singular object type from class
     *
     * @return string Lowercased classname without the Mepr
     */
    private function object_type()
    {
        $mepr_class = get_class($this);

        return strtolower(str_replace('Mepr', '', $mepr_class));
    }
}